The present invention relates to a server system, and, more particularly to a blade server that mounts multiple servers in a common enclosure in high density.
In recent years, the application of the Internet to various businesses is expanding rapidly. Accordingly, even a server system that constructs the Internet environment changes in form and supports an expanding growth of the Internet. A blade server has appeared as one of the changes to advance the high-density packaging of a server. The “blade” of the blade server is a long, thin sword-type circuit board having hardware and software for functioning as the server. The blade server realizes the high-density packaging by mounting multiple blades in an enclosure.
A blade server has typically a blade that mounts a CPU (processor), an external interface unit, a controller, a cooling system, and a power unit. The blade mounts the processor for operating as a server, and processes various information in accordance with user applications. The external interface connects the blade to a network, such as the Internet or a LAN. The controller monitors, controls, and sets the operation inside the server. The cooling system cools equipment by air cooling or liquid cooling, or the combination of these coolings. The power unit supplies the power necessary for these units. Each of these units is mounted in an enclosure. The enclosure, usually, uses mainly a standard rack of 19 inches wide in the same manner as a conventional server product. 44.5 mm high is specified as a unit (U), and the enclosure is manufactured in the height multiplied by an integer in accordance with functional performance.
Blades are mounted so that the number of blades which is necessary for users, meets the cooling performance or packaging density of an enclosure, and that the number does not exceed the number of mountable blades. These multiple blades operate individually or by scattering work. Further, a device, such as a processor, an HDD, or a memory, mounted in a blade is selected in accordance with the performance or reliability required from the view point of design. Accordingly, as the device turns into a high performance device, the size of ablaze increases. Consequently, even the enclosure must have the height equal to the size of this blade.
An interface unit is connected to multiple blades respectively, and connects between these blades and the external environment, such as the Internet or a LAN. The wiring between the interface and the blade is performed inside an enclosure using a PC board. TCP/IP or Ethernet (registered mark) is mostly used as a wired internal interface and terminated on the blade side. Further, it has at least two internal interfaces or more every blade, and enables redundant configuration or configuration in which multiple blades are simultaneously connected to a separated network. A physical interface with the Internet or LAN is made fewer than the number of blades and reduces the number of connecting cables of a server by concentrating and distributing a communication signal with a switch. Further, users can save the wiring work of a network cable connected individually every server. Most physical interfaces with the Internet or LAN use Ethernet.
A blade server has multiple blades as a server function, and an interface, a controller, a cooling system, and a power unit as common components. Accordingly, if any of these common components breaks down, multiple servers stop their operation at a time. Usually, the two respective common components or more can be mounted in an enclosure.
In regard to each component inside a blade server, as described above, multiple blades are mounted and each blade functions independently, and even a common component operates independently or has redundant configuration. Accordingly, a prerequisite is that each component is maintained individually while the component is being used. For maintenance, both-sided maintenance is enabled from the enclosure front and back sides. For example, mostly, a blade is mounted on the front side and the common component is mounted on the back side. Accordingly, the wiring between the blade and the common component is performed at the central part that separates the front and back sides.
Products having such configuration as described above are manufactured in each company, and introduced in magazines. Such examples are disclosed in the following documents. IDG Japan, Monthly Network World, Issue on June 2003, pp. 134 to 148, Test Center Report, Vol. 7, “Blade Server”, and Nikkei BP Co, Nikkei Communication, Issue of Mar. 3, 2003, p. 62, “Is a Blade Server Usable in Enterprises? Advantages in VLAN Configuration, Management, or Performance Upgrade with a Built-in Switch”, Japanese Patent Laid-Open No. 2002-057419, and U.S. Pat. No. 5,122,691. For example, Japanese Patent Laid-Open No. H11(1999)-312854 as a method of both-sided mounting of a blade server on the front and back sides characteristic of the Blade Server Mounting Method described in Background of the Invention.